Topic: Large metal ion template reaction (Read 116 times)

Hi!I have a slight problem with an undergrad question relating to a supramolecular template reaction.It states that when phthalonitrile is reacted with uranyl acetate it forms a macrocyclic complex with an intense peak in the mass spectrum at m/z 1322.4.Learning about metal phthalocyanines in the past it seems like phthalonitrile can polymerise to form a macrocycle with a suitable hole size to accommodate whatever metal ion occupies it (like this https://imgur.com/a/pwPN4V9). However, in this case, I've been having a lot of trouble finding the possible structure of this complex. Assuming that the molar mass is given by the mass spectrum I thought that you might be able to find the molar mass of the macrocycle by doing this...1322.4 g mol-1 = M(uranyl) - n*M(phthalonitrile)1322.4 g mol-1 = 270.03 g mol-1 - n*128.13 g mol-1∴n = 8.21However n should be an interger as it is stoichiometric no?This made me think there could be a possibility of a dinuclear uranyl bridge via acetate/hydroxide somehow. However, after doing a lot of similar calculations including those I never really got quite spot on the reported m/z value of 1322.4...eg. One structure I attempted to draw up to try and achieve the m/z value but I was slightly off:270*2+6*128.13+17=1325.78 g mol-1https://imgur.com/a/cENIkCo(I probably haven't drawn it correctly sorry, I think all the macrocycle bonds to the uranyl ion should be in the same equatorial plane - no clue if the conjugation makes sense or even the charge now I think of it, or if single hydroxyl bridging is even possible for dinuclear complexes )

I'm batting to figure out a plausible structure and was wondering if I was possibly missing something blatantly obvious, or if anyone had any suggestions regarding the structure? Many thanks!